1. Field of the Invention
The invention relates to a manufacturing method of shield type motor, and more particularly, to a manufacturing method of shield type motor that makes use of separating the protecting plastics from the enamel-covered coil to make the process of having a high-temperature thermosetting material be teemed into a mold without damaging the enamel-covered coil.
2. Description of the Prior Art
The manufacturing method of shield type motor of the prior art firstly provides an iron core having a plurality of bobbins. Afterward, an insulator is added to the iron core. Moreover, after each of the bobbins is wound with enamel-covered coil, a plastic cloth is pasted outside the enamel-covered coil. Finally, the structure is placed into a mold and a plastic material is teemed into the mold. After the plastic material is cool off, the shell of a shield type motor is formed.
Nevertheless, in the manufacturing method of shield type motor of the prior art, since the above-mentioned plastics in the common insulated structure of shield type motor coil is made of thermosetting material, the following shortcomings in the manufacturing process can occur. Firstly, direct teeming of the plastics is apt to thrust off the enamel-covered coil. Secondly, the glass fiber contained in the plastics can damage the insulated enamel in the exterior layer covering the coil during the flowing of the casting plastic. Thirdly, deformation can be generated in the iron core subjected to the excessive pressure during the punch-cast forming process. All of these shortcomings of manufacturing process will result in the increase in NPL ratio and excessive scrap producing, and consequently, increasing the raising of production cost.
Therefore, just how to resolve the above-mentioned problems and improve the design of the insulated structure of shield type motor coil has becomes necessary for the industry. This is the origin to have the invention,